Lower limb trauma, tendo-Achilles surgery may warrant DVT chemoprophylaxis use

Researchers found evidence in the literature for a cumulative effect of DVT risk factors such as high body mass index, immobilization and age.

Jitendra Mangwani

COPENHAGEN, Denmark — British investigators have identified low rates of venous thromboembolism associated with elective foot and ankle surgery in a systematic literature review they recently conducted.

Their research, however, revealed higher rates of venous thromboembolism (VTE) in lower limb and particularly Achilles rupture surgery, which may support the need for venous thromboprophylaxis in instances of ankle fractures or tendo-Achilles rupture surgery, according to Jitendra Mangwani, MBBS(Gold Medal), MS(Orth), MRCS(Ed), FRCS(Tr & Orth), of Leicester, United Kingdom.

In a presentation at the 12th EFORT Congress 2011, here, Mangwani said the reported evidence of VTE in elective foot and ankle surgery varies from 0% to 4%.

“I think in lower limb trauma there is better evidence for reducing the risk. In elective surgery, there is not much evidence at all,” Mangwani said.

Database review

Mangwani and colleagues systematically reviewed a handful of standard databases, including MEDLINE and EMBASE, for key words related to deep vein thrombosis (DVT) and VTE in foot and ankle surgery. They excluded case reports, expert reviews and studies of less than 20 patients, ultimately identifying 28 papers for the analysis. Mangwani and a co-investigator then used the 10-criteria modified Coleman scoring system (0 to 100 points) to score the quality of the data.

Two studies — one each from the United States and Sweden — showed a low incidence of VTE in the general population.

“There is a background incidence in the general population and we do not know the exact incidence of VTE in our local population,” Mangwani said.

From the elective cases studied, which included one level 2 randomized controlled trial, it appeared the evidence was low for VTE, he said. For example, one study identified a 0.15% non-fatal pulmonary embolism rate.

Trauma-related DVT

Concerning related trials, “What we’ve got in terms of assessing the data for review is not great there,” according to Mangwani.

Published studies concerning trauma cases, such as ankle fractures, revealed a 5% DVT rate. Since these patients were asymptomatic, surgeons did not treat them. Therefore, Mangwani questioned in his presentation whether clinicians need to treat below the knee asymptomatic DVT and if the DVT prophylaxis actually reduced the patient’s risk.

“Achilles tendon merits a separate mention because a lot of studies report that there is a much higher incidence,” Mangwani said, noting that in their study Lapidus and colleagues identified “a really high incidence” of DVT in this same population; 34% and 36% in patients receiving prophylaxis and placebo, respectively.

“There is some evidence for a cumulative effect” of foot and ankle surgery DVT risk factors, including age, high body mass index and immobilization, Mangwani said.

Policies, further research needed

Some local and national policies have been established to guide foot and ankle surgeons in selecting DVT prophylaxis. For example, in January 2010 the U.K. National Institute for Clinical Excellence issued related guidelines. “There was a huge change of practice as a result,” Mangwani noted.

But, according to Mangwani, little is still known about the cost-benefit of using chemoprophylaxis in these cases as none of the studies he and his colleagues reviewed mentioned this aspect of the treatment.

“We do need large, multicenter randomized trials with people who are interested in the subject to come together both nationally and internationally and take it further,” he said. – by Susan M. Rapp

References:

• Lapidus LJ, Rosfors S, Ponzer S, et al. Prolonged thromboprophylaxis with dalteparin after surgical treatment of achilles tendon rupture: a randomized, placebo-controlled study. J Orthop Trauma. 2007;21(1):52-57.
• Mangwani J, Cichero M, Irby S, et al. What is the evidence for venous thromboprophylaxis in foot and ankle surgery? A systematic review of the literature. Paper #3220. Presented at the 12th EFORT Congress 2011. June 1-4. Copenhagen, Denmark.

• Jitendra Mangwani, MBBS(Gold Medal), MS(Orth), MRCS(Ed), FRCS(Tr & Orth), consultant trauma and orthopaedic surgery at University Hospitals of Leicester, can be reached at Leicester Royal Infirmary, Infirmary Square, Leicester, LE1 5WW United Kingdom; +44-116 258 5085; email: jitendra.mangwani@uhl-tr.nhs.uk.
• Disclosure: Mangwani has no relevant financial disclosures.

This study highlights some of the controversies that exist around thromboprophylaxis in foot and ankle surgery. Whist it is accepted that there is a potentially increased risk of thromboembolic disease following lower limb surgery the exact incidence, risk and potential sequelae are poorly documented. Part of the problem is that, with a generally accepted low risk of VTE following foot and ankle surgery, large numbers of patients need to be studied, and within that study group a wide range of variables exist. Some of these variables, e.g., tendo-Achilles surgery, appear to have an increased risk of VTE.

With few hard facts to guide surgeons it is imperative that part of the consenting process prior to surgery involves a discussion between surgeon and patient as to the pros and cons of using thromboprophylaxis. The discussion should take the form of a risk assessment for thromboembolism occurring and the potential for postoperative bleeding or heparin-induced thrombocytopenia (HIT). Surgeons may be helped by recent guidelines that have been produced by the British Orthopaedic Foot & Ankle Society and are available on their website

— Rhys H. Thomas, FRCS Orth, FFSEM
Consultant Trauma and Orthopaedic Surgeon
Cardiff and Vale University Health Board
Wales
Disclosure: Thomas has no relevant financial disclosures.